The primary objective is to examine the nature, distribution, functional roles, metabolism and fate of the lipids of each of the stages in the life-cycle of a pseudophyllidean cestode, by chromatographic, radiochemical and spectroscopic analyses. A secondary objective is to maintain the life-cycle of the cestode, Spirometra mansonoides, in the laboratory and to simplify and improve upon current procedures for obtaining very large yields of each stage (egg, coracidium, procercoid, plerocercoid, adult); for the proposed studies and to supply such material to other investigators.